Assembly to administer insulin from a cartridge

ABSTRACT

An assembly for the administration of a selected dosage of insulin or other medicaments from a cartridge by moving a plug guided in said cartridge, comprises an adapter assembly for adapting cartridges with different dimensions or contents. The adapter assembly comprises a first threaded element threaded with a thread lead and movable in a moving direction to move the plug, and a second threaded element threaded with a thread lead for setting a selected dosage, pivotably screwed to said first threaded element and limiting the movement of said first threaded element, and wherein said thread lead of said first element and said thread lead of said second threaded element are adapted to the dimensions and/or the contents of said cartridge.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is filed herewith for the U.S. National Stageunder 35 U.S.C. § 371 and claims priority to PCT applicationPCT/EP2010/054383, with an international filing date of 31 Mar. 2010 anda Convention priority date of 1 Apr. 2009. The contents of thisapplication are incorporated in their entirety herein.

STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

TECHNICAL FIELD

The invention relates to an assembly to administer a selected dosage ofinsulin or other medicaments from a cartridge by feed movement of a plugmovably guided in the cartridge.

BACKGROUND OF THE INVENTION

Such application assemblies are particularly employed in insulin therapyfor diabetes mellitus. In insulin therapy, particularly in theintensified insulin therapy and conventional insulin therapy, insulin isnot applied in constant amounts. In conventional insulin therapy insulinis applied at pre-scheduled times. The daily routine of a patientcomplies with such times. In intensified conventional insulin therapy abasal requirement of insulin is provided, often by a slow acting andlong lasting insulin, the basal insulin. At meals, a fast-acting insulinis applied. The dosage of the fast-acting insulin is essentially basedon the comprised carbohydrates. The dosage is hence specifically chosendepending on external circumstances. Such circumstances are, forexample, the time of the day, the amount of exercise, the diet and thelike.

Diabetes mellitus can have severe long-term consequences and impairmentof the body. They can be considerably reduced by means of an adaptedinsulin therapy, preferably an intensified conventional insulin therapy.A wrong dosage can also have short term effects like hypoglycemia. Anoptimal adjustment of the dosage to the respective circumstances is,therefore, highly desirable.

For this reason diabetes mellitus patients are urged to take minutes oftheir lifestyle and applied doses of insulin. The record keeping is timeconsuming. The record usually comprises the measured blood sugar level,the consumed amount of carbohydrates, the applied dosage of insulin aswell as time and date. The attending physician or the patient candetermine or adjust the respective dosage using this record.

The administration of insulin is carried out with an injection aid (alsoknown as pen), that is provided with an injection needle and a cartridgecontaining the medicament or with an insulin pump with a cartridge. Theinsulin pump is employed continuously whereas a pen is employed forsingle application procedures.

Known pens externally resemble a large ball pen. They comprise a housingand a cartridge. Cartridge is understood to be a cylindrical ampoulehaving a puncturable membrane on one side. The other side is closed by amovable plug. The medicament is contained in the cartridge. Thecartridge is usually exchangeable. However, assemblies are known thatare provided as disposable pens. Cartridges, their content, dimensionsand their handling are not standardized. Therefore, a cartridge of onemanufacturer can normally not be inserted into a pen of anothermanufacturer.

A pen comprises a measuring device. The required dosage is adjusted witha dose setting knob. It is then applied into the hypodermic fat tissue.Some pens display the adjusted dosage on a display with electricalenergy instead of a mechanical display. The display is driven by a coincell. The patient can adjust the dosage and note it down in the record.The diabetes log is shown to a physician. The physician can work out thefurther therapy together with further body parameters i.e. blood sugarvalues, body measurements and blood pressure.

Keeping records according to known methods is time consuming. It canlead to carelessness of the patient. There is a danger of knowingly orunknowingly wrong recording of the insulin dosage. This can, forexample, occur if the patient acts contrary to the physician'sinstructions. The patient usually does not like to disclose a faultyself medication. Hence, the data on the record and the adaption of theprospective therapy will be wrong. The patient will suffer severe acuteor long term consequences.

DE 101 47 973 A1 discloses an assembly where sensors are provided forthe detection of the kind of cartridge in order to prevent mistakes. Forthis purpose, sensors are attached to the assembly, which interact withcognitional elements on a cartridge. Thereby, the medicament in acartridge unambiguously read out.

DE 10 2005 018 305 A1 discloses an application assembly, where a dosageapplication knob is secured against accidental actuation. An adjustmentring is provided on one end of the application assembly for adjustmentof a dosage. The dosage application knob is positioned separate from theadjustment ring and only serves for the application of an adjusteddosage. The applied dosage can be adjusted with the adjustment ring. Theactuator is glidingly held in the adjustment ring. By rotating theadjustment ring the dosage application knob is displaced in axialdirection. The actuator never rises beyond the adjustment ring. Thisserves as securing means to prevent that the dose is accidentallyactuated.

In the prior art it is disadvantageous that the patient must usedifferent pens for insulin of different manufacturers. This forces thepatient to learn a new handling. Furthermore, it is disadvantageous thatdifferent insulin pens are provided with different security mechanismsto prevent accidental activation.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to provide an assembly of theaforementioned kind that is more cost effective an easier to handle. Itis a further object of the invention to provide an assembly with a moresecure handling.

According to the present invention this object is achieved with anapplication assembly of the aforementioned kind by

(a) an adapter assembly to adapt cartridges with different dimensions orcontents, comprising

(b) a first threaded element movable in a moving direction to move theplug, and

(c) a second threaded element for adjusting a selected dosage, pivotablyscrewed to the first threaded element and limiting the movement of thefirst threaded element, wherein

(d) the thread lead of the first and the second threaded element isadapted to the dimensions and/or the contents of the cartridge.

Insulins of different suppliers are offered in different cartridgesizes. An assembly according to the invention enables the user to usethe same pen for insulins of different suppliers. This reduces thepurchase costs, because there is no need to buy a new pen upon change ofthe medicament. The user has the advantage that he does not need to getused to the handling of a new application assembly. The handling is,therefore, facilitated and more secure.

Cartridges provided by different suppliers may have different outerdimensions. Hence, a cartridge of a different supplier can usually notbe inserted into the pen known in the art. An adapter assembly willcompensate such drawbacks. Cartridges provided by different suppliersmay be used. The flank lead of the threaded elements defines the feedmovement of the plug. Thereby, it is ensured that the applied dosagedoes not depend on the shape of the cartridge. An individual specificflank lead is assigned to each kind of cartridge.

The invention is based on the finding that the integration of threadedelements with matching flank leads allows the use of differentcartridges. The cartridges may have different dimensions and contents.Accordingly, the feed movement of the plug is different for differentcartridges.

Preferably, the assembly comprises a pivotable dose setting knob andmeans for transferring the rotational movement of the dose setting knobto the second threaded element. In particular, the dose setting knob maybe locked. In a particularly preferred embodiment of the presentinvention a housing is provided, the dose setting knob adapted to bepressed inside against the force of a pressure spring in the housing andwhich dose setting knob is adapted to be releasably locked therein. Thedose setting knob operates similarly to the mechanics of a ball pen. Inorder to use the assembly the dose setting knob is released and ispushed outside by the spring. It may then be rotated in the desired way.The dose is selected by rotation. The rotational movement is transmittedto the threaded element. In order to administer the medicament the dosesetting knob is pushed. If the assembly is not used the dose settingknob is pressed inside and secured against accidental actuation.

According to a modification of the invention it is provided, that

(a) the first threaded element is formed by a threaded rod with anexternal, male thread,

(b) the adapter assembly comprises a casing having an open side forreceiving a cartridge and which is provided with an aperture at itsopposite end for guiding the threaded rod in a rotationally secured way,and

(c) the second threaded element is formed by a nut, screwed on thethreaded rod from the outside of the casing, the axial position of whichis selected by rotation.

The production of such an assembly is cost effective and the design issimple. It is understand that it is possible to use a threaded hollowshaft or the like. Any other securing means may be used instead of acasing for an adapter.

Preferably, securing means may be provided to block a movement of thethreaded rod in an opposite movement direction.

The securing means ensure that the adapter may be used only once. Withthe securing means the threaded element cannot be returned to thestarting position. Once insulin has been applied no new cartridge can beinserted. The adapter needs to be replaced. The mechanical wear and tearof the components is reduced because the adapter can only be used once.The application assembly works more precise and more reliable.

Preferably, the securing means are formed by a securing disk attached tothe threaded rod inside the casing which is locked by the cartridge.

The securing means can be formed by a disk attached to the threaded rodwith an opening between the front end of the cartridge and the innerfront end of the casing and having flexible tongues in the range of theopening engaging with the thread of the threaded rod.

Such a securing disk is cost effective in production and reliable inhandling. It is understood that the securing means can also be providedat the casing.

In a preferred embodiment of the invention a sensor assembly is providedfor contactless registration of the applied dosage. By not usingmechanical parts wear and tear is reduced and therefore, the reliabilityof the application assembly is improved. The sensor assembly maycontain:

(a) magnets on one of the rotating components for adjusting the dosage,

(b) magnetic sensors detecting the rotation of the magnets, and

(c) processing, and display means for processing and/or displaying adosage corresponding to the detected movement determined from thedetected rotation.

Magnets are well suited for the contactless transmission of signals,because magnetic fields are spatially extended. Sensors can detectmagnetic fields without being in mechanic contact to the magnets. Themagnetic fields of magnets remain constant over a long period of time,thus the reliability of the application assembly is improved.

Preferably, means are provided for determining and registering the timeand/or the date and means for determining and registering the selectedand administered dosage. By saving the date and/or the time togetherwith the adjusted dosage the patient can easily monitor when he appliedinsulin for the last time. For basal insulin it is important to meetexact application times of insulin. This is realized by the indicationof the elapsed time since the last administered dosage. With such anarrangement the patient can control when he administered the lastdosage. This is helpful if the patient wants to control the developmentof the blood sugar values since the last dosage of insulin. Furthermore,the selected dosage of insulin can be saved. The patient can thenreconstruct if the applied dosage was correctly calculated.

The date and/or the time may be transmitted to a receiver by means of atransmitter together with the signal of the applied amount of themedicament. The data may also be recorded and transmitted independently.

In order to reduce the transmission distance the signal can betransmitted to, for example, a cell phone by a short range broadcaststandard (such as, for example, Bluetooth®). The further transmissioncan then be effected by a common mobile telephone network. It isunderstood that any other transmission is also possible. Thus, theinformation may also be transmitted to a receiver which is connected tothe internet. Also, GSM and the like are suited for the transmission ofthe signal. The transmitted data may be encrypted.

The assembly can also be provided with a receiver for receiving data.Thereby, notices of receipt, warnings or any other data can be received.In particular, an assembly with a receiver enables the communicationwith the physician in charge even if another communication is notpossible.

The assembly may be provided with a display for showing warnings,transmission data, status information and the like. This facilitates thehandling.

Furthermore, the assembly may be provided with means for acoustic in-and/or output of data. During the course of the disease impaired visioncan occur for diabetics. The use of an acoustic in- and/or output ofdata ensures that even these patients can handle an injection aid.

The assembly may be provided with a touch pad for the in- and output ofdata and dosage settings. Such a touch pad can be designed for blindusers in order to enable blind users to use such an applicationassembly, too.

The energy storage can be exchangeably arranged so that thefunctionality is ensured at any time. Alternatively, the assembly may beprovided with a wireless chargeable and/or exchangeable energy storage.It may then easily remain with the patient at all times. The energystorage can be wirelessly charged by electromagnetic induction like anelectrical toothbrush.

The assembly can be used in a network for the transmission, saving andprocessing of data relating to the dosage of a medicament. The networkmay be provided with an application assembly with a transmitter for thetransmission of data relating to the selected and/or administered dosageof a medicament, a receiver for receiving the signal and a dataprocessing unit for saving and processing the received data.

Personalized data may be saved in the data processing unit and means maybe provided for processing the data transmitted by the transmittertogether with the personalized data.

The network may comprise a base station which collects data of theapplication assembly and transmits them to the data processing unit. Thesignals of the application assembly may be wireless transmitted. Thetransmission between the base station and the data processing unit maybe effected via a mobile telephone network.

Further modifications of the invention are subject matter of thesubclaims. Preferred embodiments are described below in greater detailwith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a cross section through an application assembly for insulinwith mechanical setting of the dosage;

FIG. 2 shows an adapter with a cartridge to adapt the cartridge to theapplication assembly of FIG. 1 in greater detail;

FIG. 3 is a cross section of the application assembly of FIG. 1perpendicular to its longitudinal axis;

FIG. 4 schematically shows the setup of a network for an applicationassembly according to FIG. 1 with a data processing unit where patientdata are stored;

FIGS. 5(a-f) shows cross sections along three different sectional planesof the assembly in FIG. 1 with different orientations of the dosagemeans;

FIG. 5g shows a cross section through an application assembly as in FIG.1 with the three different sectional planes of FIGS. 5(a-f) shown;

FIG. 6 is an exploded view of the mechanical set-up of the applicationassembly of FIG. 1 which controls the movement of the dose setting knobalong the longitudinal axis of the assembly;

FIG. 7 is a longitudinal cross section of an alternative embodiment ofan application assembly where the dosage is contactless measured;

FIG. 8 shows an adapter of FIG. 7 in detail with a cartridge to adapt toan application assembly for insulin;

FIGS. 9(a-c) illustrates the locking mechanism during the dosing ofinsulin with an assembly of FIG. 7;

FIG. 10a is an exploded view of the cartridge side portion of theassembly of FIG. 7;

FIG. 10b is an exploded view of the dose setting knob side portion ofthe assembly of FIG. 7;

FIG. 11a is an exploded view of a portion of the mechanical set-up ofFIG. 10b in greater detail;

FIG. 11b is an exploded view of another part of the mechanical set-upand the dose setting knob of FIG. 10 b; and

FIGS. 12(a-d) are cross sections perpendicular to the longitudinal axisof an application assembly of FIG. 7 in different positions.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 an application assembly for insulin is generally denoted withnumeral 10. The application assembly is provided with an elongatedplastic housing. The housing comprises a front portion 14, a backportion 16, an intermediate portion 15 arranged between the front andthe back portions 14 and 16, respectively, of the housing and an endportion 12. The front portion 14 of the housing is covered by anelongated cap 18.

An essentially cylindrical cartridge 20 is arranged inside the frontportion 14 of the housing. The cartridge 20 is filled with insulin. Thecartridge 20 is provided with a membrane 22. For administering theinsulin a needle (not shown) can be inserted through the membrane 22.

The cartridge 20 is also provided with a plug 24 movably guided in anaxial direction. The diameter of cartridges generally varies dependingon the manufacturer. An adapter assembly is used to account for suchvariations. The adapter assembly has an exchangeable casing 28, athreaded rod 38, a nut 40 and a disk 34 and is described below ingreater detail. Different adapter assemblies are used for differentcorresponding cartridges 20. The cartridge 20 is tightly supported inthe adapter assembly. A dose setting knob 69 described below is presentat the back portion 16 of the housing.

The adapter assembly comprises a casing 28. The cartridge 20 is arrangedinside such casing 28. The casing 28 is essentially designed as a hollowcylinder. The inner diameter of the casing 28 corresponds to the outerdiameter of the cartridge 20. The outer diameter of the casing 28corresponds to the diameter of a cylindrical interior space of the frontportion 14 of the housing. The casing 28 serves as an adapter fordifferent cartridge shapes.

The components 28, 38, 34, 40 of the adapter assembly are shown with acartridge 20 in FIG. 2 in greater detail. The casing 28 is open at thecap end in order to enable the cartridge to be inserted when the frontportion 14 of the housing is opened. The end of the casing 28 on theside of the dose setting knob 69 is closed and is provided with acentral aperture 30. The aperture 30 is a circular opening with threeinwardly rising radial projections. On the side of the dose setting knob69 the front end of the cartridge 28 is provided with axial projections32 form-fittingly engaging with depressions in the intermediate portion15. Thereby, the casing 28 is secured against rotation.

The disk 34 essentially consists of sheet metal and is arranged adjacentto the closed end of the casing 28 on the side of the dose setting knob69. The disk 34 is clamped between the cartridge 20 and the closed endof the casing 28. This is shown in FIG. 2. In FIG. 2 the disk isseparately shown outside the casing 28 for better illustration. The disk34 is also provided with a central opening 36. The opening 36 is starshaped. Thereby, small, concentric elastic sheet metal tongues 37 areformed. The number of elastic sheet metal tongues 37 depends on thesymmetry of the star shaped opening 36. In the present case the disk 34has six sheet metal tongues 37. Obviously, any other number of tonguesis also suitable. The threaded rod 38 may be moved in an axial directionfrom the top in FIG. 1 through the aperture 30 and the opening 36 in thedisk 34.

The threaded rod 38 is shape such that it corresponds to the form of theaperture 30. Thereby, the threaded rod 38 is secured against rotationwith respect to the casing.

The threaded rod 38 is provided with a male, exterior thread. Theelastic sheet metal tongues 37 engage with the threads of the threadedrod 38. Upon axial movement of the threaded rod 38 in the direction ofthe cartridge 20 the metal sheet tongues 7 are slightly bent. A movementof the threaded rod 38 in the reverse direction is prevented by themetal sheet tongues 37. The threaded rod 38 can only be axially moved inthe direction of the cartridge. Insulin is pushed through the injectionneedle like a syringe upon axial, in FIG. 2 downward movement of thethreaded rod 38 and the plug 24.

A nut 40 with a female thread is screwed onto the threaded rod 38outside the casing 28. On its outside the nut 40 is provided with radialcams 42 for guiding the nut. Before putting a full cartridge into usethe nut 40 touches the end of the casing 28 at the side of the dosesetting knob. This is shown in FIG. 1. Upon rotation the nut 40 moves upin FIG. 1 relative to the casing. Thereby, a gap occurs between the nut40 and the casing 28 which is fixed to the housing. Thereby, the plug 24is not yet influenced. In order to administer insulin a pressure isapplied to the threaded rod 38 and hence to the plug 24. In doing so,the threaded rod 38 is pushed downwards in FIG. 1 in the direction ofthe cap 18.

The upper end (FIG. 1) of the casing 28 forms a stop for the movement ofthe threaded rod 38 with the nut 40. The gap generated by rotating thenut 40 corresponds to the stroke travelled by the plug and is a measurefor the administered dosage of insulin.

The slope of the thread of the threaded rod 38 is adapted to thegeometry of the cartridge 20 and the applied insulin. A cartridge with asmaller diameter requires a greater slope than a cartridge with largerdiameter for the same insulin and the same volume. One turn of thethreaded rod 38 corresponds to a certain stroke and hence anadministered dosage of insulin.

The dosing by rotating the nut 40 is carried out by means of a dosingmeans described below. The dosing means is arranged in the back portion16 of the housing. This can be seen in FIGS. 1 and 6. The adapterassembly and the dosing means serve to select the dosage.

The dosing means comprises a jacket 46 with a cylindrical socket 47.With the cylindrical socket 47 the jacket 46 is pivotably mounted in abearing sleeve 48. The inner wall of the jacket 46 is provided withaxial grooves 45. The cams 42 of the nut engage with the grooves 45 andare axially movable therein.

A rotational movement of the jacket 46 is hence transferred to the nut40. The nut 40 moves in an axial direction on the non-rotatable threadedrod 38. An axially movable, hollow shaft 50 is coaxially provided insidethe jacket 46. At its end hidden inside the jacket 46 the hollow shaft50 is provided with projections 51 extending in an axial direction alongthe circumference also engaging with the grooves 45 in the inner wall ofthe jacket 46. The jacket 46 hence follows a rotation of the hollowshaft 50.

The hollow shaft 50 is provided with a thickened portion 52 along thecircumference at its dose setting knob end. The thickened portion 52extends over a cylindrical range 54 ending at a surrounding edge 55 witha larger diameter. The thickened portion 52 serves as a counter bearingfor a pressure spring 53 coaxially arranged around the hollow shaft 50.The pressure spring 53 is shown in FIG. 1. The counter bearing of thepressure spring 53 on the side of the cartridge is formed by the bearingsleeve 48.

The pressure spring 53 pushes the hollow shaft 50 from the jacket 46.The stroke is limited by a release spring 96 stopping the surroundingedge on the side of the dose setting knob. The release spring 96 isshown in FIG. 1. There is a gap between the nut 40 and the hollow shaft50.

If the patient rotates the hollow shaft 50 the nut 40 is shifted in thejacket 46 in the direction of the dose setting knob 69. Thereby, the gapbetween the hollow shaft 50 and the nut 40 is reduced. At the same timethe gap between the upper end, in FIG. 1, of the casing 28 and the nut40 is increased. By exertion of a force onto the hollow shaft 50downwards in FIG. 1 the compression spring 53 is compressed. The gapbetween the hollow shaft 50 and the nut 40 is reduced. Once the hollowshaft 50 touches the nut 40, the nut 40 moves in the direction of thecap 18 upon further application of a force onto the hollow shaft 50. Asthe nut is connected to the threaded rod 38 by the thread the threadedrod is shifted in the direction of the cap 18 until the nut meets thedose setting knob end of the casing 28.

The range 54 is surrounded by a conducting tube 56. The conducting tube56 is shown in FIG. 1. Metal contacts are attached to bearing sleeve 48on the side of the dose setting knob. A switch is formed by interactionwith the conducting tube 56.

Closing the switch indicates that insulin is administered. The openingof the switch is used as a switch-on post. In a different embodiment(not shown) a magnetically induced sensor mechanism is provided whichrealizes the switching operations by moving a magnet fixed to thebearing sleeve 48 relative to a magnetic sensor attached to a printedcircuit board.

On its outside the jacket 46 is divided into three portions. A firstportion is provided with several radial projections 59 on thecircumference. Movable latching elements 33 a and 33 b (shown in FIG. 3)provided in the back portion 16 of the housing engage with theprojections 59. Thereby, the rotational movement of the jacket 46 isdivided into angular steps. The division is chosen in such a way thatevery latching in the next position corresponds to a rotation of thehollow shaft 50 by 30°.

A second portion of the jacket 46 is provided with three axial cam discs61, 130 and 132. Each cam disc 61 comprises two diametrically oppositecams 134, 136, 138, 140, 141 and 142. The cam discs 61 are angularlydisplaced by 60° with respect to each other. A spring contact 63, 144and 146 is provided in the back portion 16 of the housing on the sameaxial level as each cam disk 61, 130 and 132. This is shown in FIG. 5.The spring contacts 63, 144 and 146 are attached to a circuit board 60.The circuit board 60 is positioned in the back portion 16 of the housing(FIG. 3).

Upon rotation of the jacket 46 the spring contacts 63, 144 and 146 arealternately moved by the cams 134, 136, 138, 140, 141 and 142. Thereby,the contacts are opened or closed. FIG. 5 shows the cams 134, 136, 138,140, 141 and 142 and the position of the spring contacts 63, 144, 146for a counter-clockwise rotation. A counter-clockwise rotation resultsin positions shown in the spreadsheet below. A closed contact isrepresent by 1 an open contact by 0.

FIG. pivot angle cam disk A cam disk B cam disk C 5a 0° 1 0 0 5b 30° 1 10 5c 60° 0 1 0 5d 90° 0 1 1 5e 120° 0 0 1 5f 180° 1 0 1

Starting from a position with a pivot angle of 0° a counter-clockwiserotation leads to the following encoding for the first 30° rotation:

pivot angle cam disk A cam disk B cam disk C 0° 1 0 0 −30° 1 0 1

The rotating direction of the jacket 46 can be unambiguously assigned bythe order in which the contacts open (0) and close (1). A correspondinginsulin dosage is related to the sequence of the switch positions. Thethird contact essentially serves for reliability and can be used todetect errors.

The hollow shaft 50 is provided with a first claw 65 on the side of thedose setting knob. This is shown in FIG. 6. A second claw 67 of anextension 62 engages with the first claw 65 of the hollow shaft 50. Theextension 62 is also hollow. The second claw 67 is provided on the capside of the extension 62. The dose setting knob 69 is attached on theother side of the extension. When the patient rotates the dose settingknob, the extension 62 follows the rotational movement. The extension 62transmits the rotation through claw 67 to claw 65. A rotation of thedose setting knob is hence transmitted to the hollow shaft 50 andthrough the hollow shaft to the nut 40.

The claws 65 and 67 allow an axial movement of hollow shaft 50 andextension 62 with respect to each other due to the presence of a gap. Ashoulder 71 is provided at the second claw 67 on the side of the dosesetting knob. The extension 62 is conical beyond the shoulder. On theside of the dose setting knob the shoulder 71 is provided with a spurgearing 70.

An infeed jacket 66 is shifted over the extension 62. The infeed jacket66 has two sides: on the side of the cap 18 and one on the side of thedose setting knob 69. A spur gearing 72 is provided on the side of thecap 18 the spur gearing engaging with the spur gearing 70 of theshoulder 71.

Four angularly symmetrical guiding rails 74 are provided along theoutside of the infeed jacket 66. A ring 76 on the side of the capconnects the guiding rails 74 with the infeed jacket 66. The ring 76 isprovided with a tooth shaped wave track 78 on the opposite side. Thetooth shaped wave track 78 is interrupted by the guiding rails 74. Onthe side of the dose setting knob 69 the end of the guiding rails 74 isprovided with a saw tooth shape.

The dose setting knob end of the infeed jacket 66 is provided with afirst tooth shaped structure 80 cooperating with a second tooth shapedstructure 82 of a push jacket 68. The push jacket 68 is also coaxiallyarranged on the extension 62. At its cap end the push jacket 68 isprovided with projections 84 on the outside.

A guiding bushing 86 is rotatably beared in the back portion 16 of thehousing. Therefore, the guiding bushing 86 is provided with a brim 88 onits outside. Corresponding to the brim 88 a radial groove 90 is providedin the back portion 16 of the housing. The brim and the radial grove 90form a bush bearing. In an alternative embodiment which is not shown theguiding bushing 86 is not rotatable.

The guiding bushing 86 is provided with guiding grooves 92. The numbersof guiding grooves 92 correspond to the numbers of projections 84 of thepush jacket 68 and the numbers of guiding rails 74 of the infeed jacket66. The push jacket 68 is axially movable in the guiding bushing 86. Adose setting knob end of the guiding bushing is provided with a block 94for the infeed jacket 66. The block 94 is shown in FIG. 1.

The cap end of the guiding bushing 86 is provided with a saw toothshaped spur gearing 98 that correspond with the saw tooth shaped ends ofthe infeed jacket 66. The saw teeth 98 of the guiding bushing 86 areformed in such a way that a guiding groove 92 is arranged after everysecond steep flank.

The above mentioned release spring 96 is arranged axially between thehollow shaft 50 and the infeed jacket 66. The release spring 96 is shownin FIG. 1. The release spring pushes both claws 65 and 67 apart.

The spring constant of the release spring 96 is larger than the springconstant of the pressure spring 53. Hence, in first approximation thepressure spring 53 is compressed first before the release spring 96.

The release spring 96 and the pressure spring 53 load the infeed jacket66 with a force acting in the direction of the dose setting knob 69.Thereby, the infeed jacket 66 is pushed against the guiding bushing 86.

If the infeed jacket 66 engages with its guiding rails 74 in the guidinggrooves 92 the infeed jacket 66 moves by the spring force of thepressure spring 53 in the direction of the end portion 12. Together withthe infeed jacket 66 the push jacket 68 moves in the guiding bushing 86until the projections 84 of the push jacket 68 reach the block 94 of theguiding grooves 92 in the guiding bushing 86. This defines the firstposition of the infeed jacket 66. The dose setting knob 69 is nowaccessible and can be rotated and otherwise operated.

By pushing the dose setting knob 69 at first the pressure spring 53 iscompressed. The push jacket 68 moves in the direction of the cap 18.Thereby, the infeed jacket 66, the extension 62 and the hollow shaft 50are also moved in that direction. When the conducting tube 56 reachesthe metal contacts at the bearing sleeve 48, the switch is closed.

Thereby, the administered insulin dosage is saved. Additionally, a timestamp is generated and saved in a memory. The insulin pen is in anenergy saving mode.

The release spring 96 is compressed by further pressure on the dosesetting knob 69. Thereby, the distance between the claws 65 and 67 isreduced. When the guiding rails 74 of the infeed jacket 66 are notguided by the guiding grooves 92 of the guiding bushing 86 the infeedjacket 66 is turned further one saw tooth of the guiding bushing 86 bythe spur gearing between push jacket 68 and infeed jacket 66.

There are no guiding grooves corresponding to the guiding rails 74 ofthe infeed jacket 66. If the dose setting knob 69 is not pushed anymorethe release spring relaxes and pushes the infeed jacket 66 against theguiding bushing 86. The infeed jacket 66 is locked in that position.

In this position the dose setting knob 69 is hidden in the housing ofthe assembly. The dose setting knob 69 is secured against accidentalactuation.

With repeated pushing of the dose setting knob 69 in the direction ofthe cap 18 the release spring is compressed. The push jacket 68 pushesthe infeed jacket 66 in the direction of the cap 18. When the guidingrails 74 of the infeed jacket 66 are shoved over the steep edge of thesaw tooth shaped spur gear 98 of the guiding bushing 86 by effect of thespur gear between push jacket 68 and infeed jacket 66 the infeed jacket66 is rotated further one saw tooth of the guiding bushing 86.

The guiding rails of the infeed jacket 66 now accompany correspondingguiding grooves 74 of the guiding bushing 86. Upon releasing the dosesetting knob 69 the infeed jacket 66 moves in the direction of the endportion 12. Thereby, the dose setting knob 69 moves out of the endportion 12. The dose setting knob is now accessible and can be rotatedand can be otherwise operated.

A display 100 is provided at the assembly 10. The casing is alsoprovided with a clip 102. This serves for the attachment of the assemblyto a pocket or the like. Furthermore, a color coding is provided at theback portion 16 of the housing. This allows for a color coding ofdifferent insulin.

A switch 106 activates the assembly 10 upon first initiation. It isunderstood that the first activation can also be conducted by insertingbatteries. The batteries are exchangeable.

The application assembly 10 is switched on and off by operating the dosesetting knob 69. If the application assembly is switched on the lastapplied insulin dosage and the point in time of the last application aredisplayed on the display 100. A timer 110 shown in FIG. 4 determines thetime. A processor 112 then calculates the time of the day and the date.At predefined times the contents of the memory 114 are sent by a radiocircuit. The transmitted signal can also be manually triggered. A switch107 is provided for this purpose.

In FIG. 4a schematic of a network is shown. The network comprises anapplication assembly 10, a base station 120 and a data processing unit130.

The application assembly comprises the memory 114, a sending andreceiving arrangement 116 and a timer 110. The application assembly 10can communicate with the base station 120. Therefore, a sending andreceiving arrangement 122 is provided in the base station.

The communication is bi-directionally established by radio frequencies,for example in the frequency range of 868 MHz. Upon insertion of thebatteries the application assembly 10 searches for the base station 120.Radio signals are emitted for this purpose.

The base station 120 receives this signal and sends a signal to theapplication assembly 10. Then, the timer 110 inside the applicationassembly 10 is started. The base station 120 also transmits the nextcommunication time to the application assembly 10. The applicationassembly then sends a signal to the base station 120 at predefinedtimes.

If the application assembly does not receive a signal from the basestation within a certain time interval the application assembly stopsbroadcasting. Thereby, the battery of the application assembly 10 is notunnecessarily used up.

If communication with the base station is established the applicationassembly 10 broadcasts the saved, applied insulin dosages with thecorresponding timestamp. The base station 120 transmits the datareceived from the application assembly 10 to a data processing unit 130.

This transmission is carried out by a modem 124 provided in the basestation 120. In the present embodiment the modem uses the mobile networkstandard GSM. The base station 120 logs in the data processing unit viamodem 124. Subsequently, data are exchanged. The data in the dataprocessing unit are accessible by a web interface. The web interfaceallows for settings at the base station or at the application assembly.

An alternative embodiment of an application assembly generally denotedwith numeral 300 is shown in FIG. 7.

As in the previous embodiment the application assembly 300 is providedwith a casing 312 with a cap 318 and a cartridge 320, which is separatedinto a front portion of the casing 314 and a back portion of the casing316. The cartridge 320 is provided with a membrane 322 and a plug 324.The cartridge 320 is held in an adapter assembly to adapt cartridges ofdifferent suppliers and dimensions to the present application assembly.A switch 490 detects whether an adapter assembly is inserted.

The adapter assembly of the present embodiment comprises, as in theprevious embodiment, a casing 328, a threaded rod 338, a disk 334 and adisk 340, as well as an additional plunger 339. The components of theadapter assembly are separately shown in FIG. 8 in greater detail. Thefunctionality of the adapter assembly does not essentially differ fromthe adapter assembly of the above described embodiment. The cap side ofthe plunger 339 is clipped to the threaded rod 338. Therefore, thepressure is evenly distributed on the plug 324.

The dose setting knob end of the casing 324 is closed and is providedwith a central aperture 330. The aperture 330 is a circular opening withtwo inwardly rising radial projections. The profile of the threaded rodis provided with two corresponding depressions 329 and 331.

The disk 334 is provided with an oval opening 336 adapted to the crosssection of the threaded rod. The edge of the opening 336 is partiallyprovided with radial slits. Thereby, small concentric tongues 337 areformed of elastic sheet metal. The threaded rod 338 extends through theaperture 330.

The nut 340 follows the rotation of the dose setting knob 402 by amechanical design described below. The cap side of the nut 340 isprovided with a saw tooth shaped spur gear 341. The spur gear 341 of thenut 340 engages with a corresponding spur gear 343 at the casing 328.The slope of the saw teeth correspond to the slope of the thread of thethreaded rod 338. Thereby, it is ensured that only predefined units canbe administered.

The functional principle of the dosing is illustrated in FIGS. 9(a-c).Before application both toothings are on top of each other. This isshown in FIG. 9 a. If the nut 340 on the threaded rod is rotated thetoothing 341 is shifted against the toothing 343. The inclined edges ofthe toothing are still in touch. A force F that acts in the markeddirection does not lead to an axial movement of the threaded rod. Thiscan be seen in FIG. 9 b. When the nut is shifted so far that the steepflanks of the toothing face each other the threaded rod can be moved inthe direction of the cap by the marked force F. This is shown in FIG. 9c. The mechanism improves the accuracy of applications.

The cap 318 is formed by a tube 350 with an essentially triangular crosssection. This can be well seen in FIG. 10 a. One end of the triangulartube 350 is closed by an end piece 352. The front portion of the casing314 serves as reception for the casing 328 of the adapter assembly 327.The plunger 339 and the disk 334 are arranged in the casing 328. The nut340 and the threaded rod 338 extend into the back portion of the casing316. This can be seen in FIG. 7. The portion of the casing 316 comprisesan elongated corpus 356 also having an essentially triangular crosssection. This is shown in FIG. 10 b. An intermediate piece 354 islocated between the portion of the casing 314 and the corpus 356.

The intermediate piece 354 is provided with a bayonet coupling havingthe front portion of the casing 314 attached thereto. The intermediatepiece 354 is provided with depressions 360 that engage with projections332 in the casing 328. The casing 328 is hence secured against rotation.

A display and control panel 372 is fitted into the corpus 356. Thedisplay and control panel 372 comprises a display window 374 and anoperator panel 376. A control sensor 380 which is addressed by thecontrol panel 376 is located on a display circuit board 378.Furthermore, a display 382 is located on the display circuit board 378.

A slit 362 for a battery holder 364 is provided at the corpus 356. Thebattery holder 364 holds batteries or accumulators 366, 368 and 370providing the application assembly 300 with electricity. The batteryholder 364 holds the batteries 366, 368 and 370 in a battery compartment384. The battery compartment 384 is also provided in corpus 356.

A contact strip 386 connects the plus terminal of the batteries 366, 368and 370 with the display circuit board 378. The negative terminal of thebatteries 366, 368 and 370 is connected to the display circuit board 378via a sheet metal tongue 388.

A clip 390 is attached to the battery compartment 384 by a screw 392. Aclip cover 394 covers the screw 392.

A sensor circuit board 396 is electrically connected to the displaycircuit board 378. Two magnetic sensors 397 and 398 are provided on thesensor circuit board 396. An ON-sensor 399 is also provided on thecircuit board. A knob enclosure 400 forms one end of the corpus 356.

The actual mechanical design of the application assembly comprises, fromthe right to the left: the dose setting knob 402 the knob enclosure 400,a hat element 404, a crown 406, a counter crown, 408, a balance spring410, a securing ring 412, a block 414, a ring magnet, 416, a pressurespring 418, a shaft 420, a coupling element 422 and a latch element 424.The interaction of the components is described below with reference toFIGS. 11a and 11 b.

The coupling element 422 connects the nut 340 to the shaft 420. Thecoupling element 422 is rotationally symmetrical about a longitudinalaxis of the application assembly 300. The coupling element 422 ispivotably mounted in a space formed by the display—and control panel 372and the battery compartment 384.

The coupling element 422 is provided with a longitudinal bore hole 426.The inner wall of the coupling element 422 is provided with guidinggrooves 428. The attachments 342 provided on the nut 340 are guided inthe guiding grooves 428. The nut 340 is movable along the axis of thecoupling element 422 and follows the rotation of the coupling element422. As the nut 340 is located on the threaded rod 388 it 340 moves inthe axial direction of the coupling element 422.

A shaft 420 is guided in the coupling element 422. Radial, outwardlyprojecting noses 430 are provided with at the end of the shaft hidden inthe coupling element 422, the noses cooperating with the guiding grooves428 of the coupling 422. The shaft 420 is movable in an axial directionalong the guiding grooves 428. The coupling 422 is charged with thespring force of a pressure spring 418. On the side of the dose settingknob the shaft 420 has a reduced diameter for receiving a securing ring412.

The coupling element is provided with a circumferentially thickenedportion 431. On the cap side of the thickened portion 431 a saw toothprofile 432 is provided. The saw tooth profile 432 engages with acorresponding profile 343 of the latch element 424.

Upon, for example, clockwise rotation of the shaft 420 the saw teethdisabling and the coupling element 422 moves against the spring force ofthe pressure spring 418. As soon as the steep flanks of the saw teethface each other the pressure spring 418 relaxes and shifts the couplingelement 422 against the latch element 424.

This movement is audible as well as tangible. The latch element 424 andthe coupling element 422 form an acoustic and haptic feedback forsetting a selected dosage by rotation.

In order to provide a feedback upon rotation in the opposite direction,i.e. in this example counter-clockwise, the latch element is providedwith another spur gear 436 on the opposite side. This is directed in theopposite direction and engages with a saw tooth profile 438 that isprovided on the dose setting knob side of the intermediate portion 354.Upon rotation in a clockwise direction the teeth of the spur gear 436and the saw tooth profile 438 jam. The coupling element 422 and thelatch element rotate with respect to each other and provide thefeedback. Upon a rotation in a counter-clockwise direction the effectreverts. Latch element 424 and coupling element 422 jam up and the latchelement moves with respect to the intermediate piece 354 whereby therespective toothing provide the acoustic and haptic feedback.

Six bar magnets 440, 442, 444, 446, 448 and 450 are arranged along thecircumference of the coupling element 422. The orientation is chosen insuch a way that a north and a south pole are alternatively revolving. Amagnetic field is formed between each neighboring pole running fromnorth to south pole.

The orientation of the magnetic fields is detected and processed by tomagnetic sensors 397 and 398 on the sensor circuit board 396. Theprinciple is shown in FIGS. 12(a-d). FIG. 12 shows a cross section ofthe magnets. Magnetic sensors 397 and 398 are located on the sensorcircuit board 396. The magnetic sensors 397 and 398 react on thepenetration direction of a magnetic field penetrating the sensorsurface. The signals generated by the magnetic sensors are discussedbelow on the basis of a clockwise rotation.

In FIG. 12b the magnetic sensor 397 is penetrated by a magnetic fieldbetween magnets 440 and 442. The magnetic field is oriented from top tobottom in the Figure. The magnetic sensor detects a signal that isassigned to zero. The magnetic sensor 398 is penetrated by a magneticfield between the magnets 450 and 440. In the drawing the magnetic fieldis oriented from bottom to top. The magnetic sensor detects a signalthat is assigned to one.

In FIG. 12c the magnetic fields are undefined. The sensors keep theprevious signal. Upon further clockwise rotation the directions of themagnetic field in both magnetic sensors 397 and 398 are reversed. Thisis shown in FIG. 12 d.

The output signals of the magnetic sensors 397 and 398 change. Theorientation of the magnetic fields and hence their output signal changeswith every rotation by 60°. The sequence of the changes areelectronically processed and converted into adjusted units which thenare displayed on the display 382. For illustration the following tableis shown:

magnetic field output clockwise magnetic sensor direction signal FIG.12b magnetic sensor down 0 397 magnetic sensor up 1 398 FIG. 12cmagnetic sensor 0 397 magnetic sensor 1 398 FIG. 12d magnetic sensor up0 397 magnetic sensor down 1 398 FIG. 12a magnetic sensor 0 397 magneticsensor 1 398

The counting in the other rotating direction operates likewise. It ispossible to use Hall sensors. Contrary to mechanical parts forprocessing the adjusted dosage the components of the present embodimentdo not wear off. Hence, the accuracy and the life time of theapplication assembly 300 are further improved.

The pressure spring 418 is clamped between the coupling element 422 andthe ring magnet 416. The cap side of the block 414 is provided with abroadened edge 452 with the ring magnet 416 and dose setting knob sideda smaller end. A ledge 456 is formed between the smaller end 454 and thebroadened end 452. The smaller end 454 is hidden in the counter crown408 up to the ledge 456.

The counter crown 408 is attached to the dose setting knob 402. Guidinggrooves 460 are provided in the counter crown 408. Such grooves do notbreak through the cap end 462. Corresponding guiding rails 464 of theshaft 420 run in the guiding grooves. The shaft 420 is biased by abalance spring 410 between shaft 420 and doses setting knob 402. Thesecuring ring 412 limits the path of the guiding rails 464 in theguiding grooves 460. The balance spring 410 ensures that the nut 420 isreliably pressed against the casing 328.

The dose setting knob 402 can be hidden in the knob enclosure 400. Inthe hidden position the pressure spring 418 is biased. In its extendedposition the pressure spring is relaxed. Thus, the shaft 420 is slightlypushed off the coupling element 422. A gap appears between the nut 340and the shaft 420.

Upon rotation of the dose setting knob 402 the counter crown 408connected thereto is rotated. The rotation is transmitted onto the shaft420 through the guiding grooves 460 and the guiding rails 464. By arotation of the dose setting knob 402 the shaft 420 is also rotated in aclockwise direction. Thereby, the nut 340 is moved in the couplingelement 422 in the direction of the shaft 420. The gap between the shaft420 and the nut 340 is reduced. The gap between the casing 328 and thenut 340 is increased.

By pressing the dose setting knob in the direction of the cap the shaft420 is moved and the pressure spring 418 is compressed. The gap betweenshaft 420 and nut 340 is reduced. Upon continuous pressure on the shaft420 the nut moves in the direction of the cap as soon as the shafttouches nut. As the nut 340 is attached to the threaded rod by thethread it is also moved. The movement ends, once the gap between nut 340and casing 328 is closed. Only the pressure spring 418 is compressedthereafter.

Thereby, the ring magnet 416 is moved until it triggers the ON sensor399. In the present embodiments the ON sensor comprises a reed contact.The ON sensor generates a signal indicating that insulin has beenadministered. It also serves for switching the application assembly 300on and off.

The crown 408 is provided with a tooth shaped structure 466 at its dosesetting knob end 402. Along the outside of the crown 408 fourcircumferential guiding rails 468 are provided. A ring shaped projection470 interconnects the guiding rails 468 of the crown 408. The dosesetting knob side of the ring shaped projection is provided with a toothshaped wave track. The tooth shaped wave track is broken by the guidingrails 468. The dose setting knob end of the guiding rails 468 matchesthe tooth shaped structure 466.

A push sleeve 474 which is provided with a tooth shaped structure 476 isattached in the dose setting knob 402. The tooth shaped structure 476and the tooth shaped structure 466 form a spur gear. Projections 478 areprovided at the outer wall of the push sleeve 474. They correspond tothe guiding rails 468 of the crown 408.

The hat element 404 is pivotably mounted in the back portion of thecasing 316. For this purpose the hat element 404 is provided with acircumferential brim on its outside. Corresponding to the brim acircular groove 482 is provided in the knob enclosure 400. Brim andcircular groove 482 form a bush bearing.

The hat element is provided with guiding grooves 488. The number of theguiding grooves 488 matches the number of projections 478 of the pushsleeve 474 and the number of guiding rails 468 of the counter crown 408.The push sleeve 474 is axially movable in the hat element 404.

The cap end of the hat element 404 with the brim is provided with a sawtooth shaped spur gear 486 on the inner edge that engages with the endsof the guiding rails 468. The saw teeth of the spur gear 486 of the hatelement 402 are designed in such a way that a guiding groove 488 isarranged after every second steep flank.

The spring constant of the balance spring 410 is larger than the springconstant of the pressure spring 418.

In OFF mode of the application assembly 300 the dose setting knob 402 ishidden in the knob enclosure 400. The dose setting knob 402 is securedagainst accidental actuation. A circumferential ledge on the inside ofthe crown 406 and a thickened portion provided at the end 462 of thecounter crown prevent its slipping out of the dose setting knob 402.

For release the dose setting knob 402 is pushed in the direction of thecap. Thereby, the push sleeve 474 pushes the crown 406 so far in thedirection of the cap that the guiding rails 468 of the crown 406 arepushed over the steep flank of the saw tooth shaped spur gear 486 of thehat element 404. By effect of the spur gear between push sleeve 474 andcrown 406 the crown 406 is turned further by one saw tooth of the hatelement 404. Now guiding rails 468 face corresponding guiding grooves ofthe hat element 404.

By releasing the dose setting knob 402 the crown 406 moves towards theknob enclosure 400 by means of the spring pressure of the pressurespring 418. Thereby, the dose setting knob 402 moves out of the knobenclosure 400. The dose setting knob is now accessible and can berotated and actuated.

After adjusting the dosage the crown 406 is pushed in the direction ofthe cap by pushing the dose setting knob 402. Thereby, the shaft 420 isalso moved. The shaft 420 actuates the nut 340 that transmits itsmovement to the threaded rod 338. The threaded rod 338 pushes the plugof the cartridge to administer insulin. The ring magnet 416 movestowards the cap, whereby the administered insulin dosage is saved. Atime stamp is generated. This time stamp is filed in a memory. Theinsulin pen is shifted into an energy saving mode where the display isturned off.

As soon as the nut 340 touches the casing 328 the pressure spring 418 isfurther compressed upon pushing the dose setting knob 402 and the crown406 moves further in the direction of the cap. When the guiding rails468 of the crown 406 are not guided by the guiding grooves 488 of thehat element 404 anymore the crown is turned further by one saw tooth ofthe hat element 404 by effect of the spur gear between push sleeve 474and crown 406. There are no guiding grooves corresponding to the guidingrails 468 of the crown 406.

If the dose setting knob is not pushed anymore the pressure spring 418relaxes and pushes the crown 406 against the hat element 404. The crown406 is locked. In this position the dose setting knob 402 is concealedin the casing of the application assembly 300. The dose setting knob 402is secured against accidental actuation.

The application assembly 300 is provided with the same electronicoptions as the assembly 10.

1.-25. (canceled)
 26. A replaceable adapter assembly being adapted andconfigured to be used in a device for the administration of a selecteddosage of insulin or other medicaments from a cartridge, the devicecomprising a housing with a removable front portion and the claimedreplaceable adapter assembly comprises: (a) a cartridge with a moveableplug guided in said cartridge, (b) a first threaded element formed by athreaded rod with an external, male thread and a thread lead, movable ina first direction to move the plug; and (c) a casing having an open sidefor receiving the cartridge and which is provided with an aperture atits opposite end for guiding said threaded rod in a rotationally securedway, and (d) a second threaded element formed by a nut and threaded witha thread lead matching the thread lead of the threaded rod for adjustinga dose, pivotably screwed to said threaded rod outside of said casingand limiting movement of said threaded rod in the first direction, andwherein (d) the first and the second threaded element are integral partsof the replaceable adapter assembly and said thread lead of said firstelement and said thread lead of said second threaded element are adaptedto the dimension and/or the content of said cartridge, and wherein saidfirst and second threaded elements of said replaceable adapter assemblycorrespond to an opening of said housing of the device so as to befrontally insertable into the housing, and wherein an outer surface ofsaid case of the replaceable adapter assembly corresponds to an innersurface of said front portion of the housing so that the replaceableadapter assembly is securable in its position by connecting the frontportion to the housing.
 27. An assembly for the administration of aselected dosage of insulin or other medicaments from a cartridge bymoving a plug guided in said cartridge, comprising a replaceable adapterassembly for the reception of the cartridge, the adapter assemblycomprising: (a) a first threaded element formed by a threaded rod withan external, male thread and a thread lead, movable in a first directionto move the plug; and (b) a casing having an open side for receiving acartridge and which is provided with an aperture at its opposite end forguiding said threaded rod in a rotationally secured way, and (c) asecond threaded element formed by a nut and threaded with a thread leadmatching the thread lead of the threaded rod for adjusting a dose,pivotably screwed to said threaded rod outside of said casing andlimiting movement of said threaded rod in the first direction, andwherein (d) the first and the second threaded element are integral partsof the adapter assembly and said thread lead of said first element andsaid thread lead of said second threaded element are adapted to thedimension and/or the content of said cartridge, and wherein the assemblyfurther comprises a sensor assembly for contactless sensing the selectedand/or administered dosage, wherein the sensor assembly comprises: (a)one or more magnets on one of the rotating components for adjusting thedosage, (b) one or more magnetic sensors detecting a rotation of saidmagnets, (c) a ring magnet and an ON-sensor with the ring magnet beingadapted to move relatively to the ON-sensor so as to trigger theON-sensor when the dosage is administered and with the ON-sensor beingadapted to generate a signal indicating that the dosage has beenadministered, and (d) processing and display means for processing and/ordisplaying a dosage corresponding to the detected movement determinedfrom said detected rotation and/or for saving the administered dose,wherein the magnetic sensors internally do not comprise any mechanicallymoveable parts.